A sensor coupled to a short-range Radio Frequency (RF) device may provide wireless sensor signals to a mobile electronic device, such as a smartphone. Short-range RF wireless signals may include, for example, WiFi, Bluetooth® signals (e.g., Bluetooth 4.0) or ANT (e.g., ANT+) radio protocols. Short-range RF wireless signals may also include Near Field Communications (NFC) or Radio Frequency Identification (RFID) protocols, among other examples.
Information from internal and external sensors may need to be processed continuously. For instance, in outdoor fitness applications the sensors may be activated continuously (at least during exercise). Other applications may use context awareness sensors that must be active at all times to measure the context.
Power consumption is a large concern for these types of applications. Frequent activation of the main central processing unit (CPU) of a mobile device enacts great costs on the battery of the device. There is a lot of overhead because the main CPU draws a lot of power just to reach a ready state. If this happens too often, the power consumption may be too high.
To mitigate heavy CPU use, some systems utilize a sub-system CPU for internal sensors, which takes over some sensor message processing on behalf of the main CPU. However, such systems do not handle frequent wireless messages from external sensors. Such a need has not existed because of standardized and well defined connected setups. Also, paired connections have been used. Furthermore, wireless sensors and an “internet of things” introduce more communications to be handled.
Some sub-systems are inflexible and can only buffer messages. Other systems may utilize additional layers of programming over the mobile device radio component and/or the sensors. However, such systems are very complicated to implement and do not guard against module crashes (memory overwrites, illegal operations, indefinite loops, etc.) in the sub-system. Also, such systems may require that additional programming be pushed out to the sensors.